The present disclosure relates generally to welding power supplies, and more particularly, to systems and methods for controlling current flow through an output load of a power control circuit.
Welding power supply circuits typically convert power from a primary source to an output suitable for welding operations. The output power is provided at an appropriate voltage or current level and may be controlled and regulated according to the process requirements. Some welding processes require the output to be AC. For instance, typical high current AC outputs for gas tungsten arc welding (GTAW) or submerged arc welding (SAW) may require circuitry that efficiently generates a square wave output with a magnitude of several hundreds of amperes. Typical circuit topologies designed to meet this need include a buck converter that steps down a supplied DC voltage, a full bridge inverter that converts the stepped down DC voltage to an AC output, and an output clamp circuit that suppresses output energy caused by parasitic output inductance from welding cables during output current reversal.
Since welding operations generally require high current levels and low voltage levels at the output, an important design criterion of typical welding and plasma cutting power supply circuits is the limitation of power losses in the circuit. However, it is now recognized that traditional power supply circuits include a combination of components (e.g., buck converter, full bridge inverter, and output clamp circuit) that typically contain multiple transistors and diodes, which greatly contribute to power losses in the circuit, leading to inefficiencies in the circuit design. Indeed, it is now recognized that there exists a need for circuits that reduce the power losses in the circuit and increase the efficiency of the welding power supply.